A Holter monitor is an ECG recording done over a period of 24 or more hours. Electrodes are attached to the patient's chest and connected to a Digital Holter Recorder by lead wires. The patient goes about his/her usual daily activities (except for activities such as taking a shower, swimming, or any activity causing an excessive amount of sweating which would cause the electrodes to become loose or fall off) during this procedure. There are 2 types of Holter monitoring:
Continuous recording - the ECG is recorded continuously during the entire testing period.
Event monitor, or loop recording - the ECG is recorded only when the patient starts the recording on the Event Recorder or Loop Recorder, when symptoms are felt.
Holter monitoring may be done when arrhythmia is suspected but not seen on a resting or signal-average ECG, since arrhythmias may be transient in nature and not seen during the shorter recording times of the resting or signal-averaged ECG.
Also called: 24 hour ECG
What is an ambulatory blood pressure monitor or holter blood pressure monitor?
It is a small device, about the size of a portable radio. Typically it is worn on a belt. The blood pressure cuff on the monitor can be worn under your clothes without anyone seeing it.
This machine lets your doctor find out what your blood pressure was every 20 to 30 minutes of a day. The information collected by this machine can help you and your doctor see if your blood pressure treatment is working.
Your doctor may want you to use an ambulatory blood pressure monitor for one or more of the following reasons:
If you have "borderline" high blood pressure
If you and your doctor can't keep your blood pressure under control
If you have blood pressure problems caused by your other medicines
If you have fainting spells
The monitor may help your doctor find out if you are a person who only has high blood pressure when you are at the doctor's office, called "white-coat hypertension." If you have this kind of hypertension, you may not need to take medicine.
What happens when I wear the monitor?
The small blood pressure cuff that is connected to the monitor will automatically check your blood pressure about every 30 minutes, even while you are sleeping. You also will be asked to keep a diary of your day's activities, so your doctor will know when you were active and when you were resting. Some people feel a little sore from the frequent pressure checks.
After 24 hours of monitoring, you will take the machine and your diary to the doctor's office. The blood pressure information is transferred from the monitor to a computer. Your doctor will review the information with you and decide if your treatment program is working or if you need to make changes to it.
If more advanced diagnostic testing is needed the patient is often referred for imaging tests.
Examples of imaging tests are MUGA and Echo. For these systems to take the image at the right phase of the cardiac cycle an ECG Trigger is used.